The present invention relates generally to devices useful for insertion of steerable catheters and scopes. More particularly, the invention describes a handgrip to be positioned over the shaft of the scope such as a colonoscope allowing to measure and display insertion forces and torque throughout the procedure.
In many cases, it has been desirable to examine internal organs, passages and the like of the human body for purposes of diagnosis, biopsy, and therapeutic interventions. One method of examining the internal organs of the patient without major surgery is to insert a remote sensing device such as an endoscope into the body through a natural body orifice such as colon or a specially prepared surgical opening.
The primary area of application of the invention is for use with a colonoscope but other devices can also be used with the handgrip of the invention. Therefore, the word “colonoscope” is used throughout this description to broadly include various types of direct vision and fiberoptic endoscopes, fiberscopes, arthoscopes, laparoscopes, and other types or steerable and deflectable catheters and tubes designed to be inserted into tight openings and curved passages.
The use of steerable scopes for internal examination is not limited to medicine. Remote sensing devices can be used to examine the interior of otherwise inaccessible mechanical structures without opening them; such as aircraft wings, the walls of buildings, and the enclosed areas of any structure. In these cases, an internal examination, without putting a major opening in the structure, can help to determine the reason for mechanical failure or the level of corrosion levels.
The preferred area of interest for the device of the present invention is in medicine, and more particularly in colonoscopy. Colonoscopy is the preferred method to screen for colorectal cancer, a disease that afflicts 115,000 patients/year in the US. Several million screening, diagnostic and therapeutic colonoscopies are performed each year in the U.S. hospitals and ambulatory surgery centers. Colonoscopy requires a physician to inspect the colonic mucosal surface by applying force to a colonoscope and advancing this flexible tube through a series of stationary and movable colonic loops.
When using a colonoscope, a common problem is to be able to maneuver the inspection end of the scope and position it in proximity to the area of interest. This maneuvering is performed by a trained operator who uses a combination of visual inspection of images and tactile coordination to maneuver through the twists and turns found in the colon. The operator will subjectively sense the resistance to maneuvers by the “feel” of the instrument and anticipate the amount of force necessary to advance the device forward. The application of force to the colon and its anatomic attachments can be painful. Particularly undesirable is the frequent occurrence of excessive contact pressure on an internal tissue, which can result in perforation. Sedation with analgesia is frequently required to make the procedure comfortable. Preliminary studies suggest that there is significant variation in the forces applied and that these forces can be excessive. Operator training programs are designed to reduce the variation in technique, however training metrics remain subjective and the characterization of effective, less forceful insertion methods is not yet available. The need therefore exists to provide a device allowing an effective, low-cost method to define best practices and to implement these practices as part of training, ongoing education and quality assurance.
There is an extensive array of surgical instruments, catheters and endoscopes that can be introduced and guided into and through both solid and hollow organ systems such as gastrointestinal tract, blood vessels and heart, urologic and gynecologic systems. These devices are designed to perform a variety of functions such as illumination, introduction of radiographic contrast materials and other fluids, surgical therapies, dilation, etc.
Examples of such guiding or steering techniques and systems for catheters may be seen in U.S. Pat. No. 4,983,165 to Loiterman entitled “Guidance System For Vascular Catheter Or The Like,” U.S. Pat. No. 4,776,844 to Ueda entitled “Medical Tube,” U.S. Pat. No. 4,934,340 to Ebling et al. entitled “Device For Guiding Medical Catheters and Scopes,” U.S. Pat. No. 4,930,521 to Metzget et al. entitled “Variable Stiffness Esophageal Catheter,” U.S. Pat. No. 3,470 to Barchilon entitled “Dirigible Catheter,” U.S. Pat. No. 3,605,725 to Bentov entitled “Controlled Motion Devices,” and the Patent Cooperation Treaty (“PCT”) Patent Application No. PCT W088/00810 of Tenerz et al. entitled “Guide For Mechanical Guiding Of A Catheter In Connection With Cardio And Vessel Examination.” These catheters, however, failed to give the operator sufficient control of the distal end of the catheter and made it difficult to manipulate the distal end for specific isolation on particular sections of the body vessel or cavity.
Other steerable catheters or systems have been made to try to give the physician control of the use of the catheter during surgical procedures wherein fluids and the various tools are needed for the operation by providing a flexible tube for controlling the direction of movement of the distal end of the catheter. Examples of these other attempts may be seen in the PCT Patent Application No. PCTW091/11213 of Lundquist et al. entitled “Catheter Steering Mechanism,” European Patent Application No. 370,158 of Martin entitled “Catheter For Prolonged Access,” and U.S. Pat. No. 4,737,142 to Heckele entitled “Instrument For Examination And Treatment Of Bodily Passages.” These devices, however, still failed to provide the control and manipulation of the catheter needed for use with the surgical tools and fluids required for an operation.
The need therefore exists for a handheld force measuring attachment device to be mounted on the colonoscope tube. This handgrip device is desirable to be easy to use, inexpensive to manufacture and result in less painful and safer colonoscopies.